Randall A. Kopper

Nancy and Craig Wood Odyssey Professor of Chemistry

Ph.D., University of Kansas

Research interest: Coralsnake venom and what drives the evolution of enzymes and other compounds within venom

Coralsnakes are a group of species with highly neurotoxic venom, which has been crucial to their evolutionary success. Yet, we know very little about coralsnake venom and what drives the evolution of enzymes and other compounds within venom. A key enzyme that appears to be both highly abundant and diverse within coralsnake venom is phospholipase A2 (PLA2), an esterolytic enzyme that hydrolyzes glycerophospholipids causing potent neurotoxicity, myonecrosis, and lipid membrane damage resulting in immobilization and death of those envenomated. Unfortunately, we know almost nothing about the PLA2 in coralsnake venoms including those of the three species of coralsnakes that occur in the U.S.

Our lab studies the PLA2 enzymes in the two most dangerous coralsnake species in the U.S. to understand the evolution and activity of this polypeptide, and in particular how it varies from individual to individual based on sex, age, and geographic origin of the individual. Almost all published studies of venom have used pooled venom from numerous individuals. This yields large volumes for study, but masks individual differences. As a result, we know almost nothing about variation between individuals, yet these differences are crucial to the ecology and evolution of the organisms and of the venom compounds themselves. We have developed methods to analyze the extremely small volumes of venom obtained from individual snakes to determine the quantity and activity of PLA2 in each snake's venom. To better understand the differences in venom PLA2 quantity and activity we are also investigating the underlying genetics. In collaboration with Dr. George Harper in the Biology Department, we study the number of genes and variation within each gene that codes for the PLA2 enzyme to determine whether genetic variation underlies differences in enzyme levels or activities. The results will greatly contribute to our understanding of the evolution of snake venoms.